数据结构之链表操作

#include <IOSTREAM>
#include <IOMANIP>
#include <STRING>
using namespace std;

typedef struct Student 
{
    int id;
    char name[20];    
    char sex[20];
    struct Student *next;
}node;
typedef node * pnode;   
pnode Create();
void Print(pnode h);
void Sort(pnode h);
int Length(pnode h);
void Delete(pnode h,int num);
void Insert(pnode h,int num,char * name,char * sex);

int main()
{
    char command[10] = "1";
    pnode h;
    while(strcmp(command,"q")!=0)
    {
        cout << "请输入命令：" << endl;
        cout <<"-----------------------------"  << endl;
        cout <<"1: 创建链表"  << endl;
        cout <<"2: 插入节点"  << endl;
        cout <<"3: 删除节点"  << endl;
        cout <<"4: 链表排序"  << endl;
        cout << "5:打印链表" << endl;
        cout << "6:链表长度" << endl;
        cout <<"q:退出" << endl;
        cout <<"-----------------------------"  << endl;

        cin >> command;
        if(0==strcmp(command, "1"))
        {
            h = Create();
            Print(h);
        }
        else if(0==strcmp(command, "2"))
        {
            cout << "请输入学号，姓名，性别：\n";
            node temp;
//             cin >> temp.id ;
//             getchar();
//             cin.getline(temp.name,20);
//             cin.getline(temp.sex,20);
            temp.id = 10;
            strcpy(temp.name , "weilele");
            strcpy(temp.sex, "female");
            Insert(h,temp.id,temp.name,temp.sex);

            
        }
        else if(0==strcmp(command, "3"))
        {
            
        }
        else if(0==strcmp(command, "4"))
        {
            Print(h);
        }
        else if(0==strcmp(command, "5"))
        {
            Print(h);
        }
        else if(0==strcmp(command, "6"))
        {
            cout << "链表长度：" << Length(h) << endl;
        }
    
    }




    return 0;
}

pnode Create()
{
    pnode h;
    pnode p,q;
    bool flag = true;
    
    //建立一个头节点
    h = new node;
    h->id=0;
    strcpy(h->name,"none");
    h->next = NULL;
    p=h;


    
    int id;
    char name[20];
    char sex[20];
    //注意这里的cin无法直接读取空格隔开的元素的值
    //将数字转换成字符串？

    while (flag)
    {
        cout << "请输入学生的学号,姓名，性别：\n"  << endl;
        string str1;
        string str2;
        string str3;
        char temp;
        cin>> id ;
        char c = getchar();
        cin.getline(name,20);   // 读取一行数据,允许中间出现空格
        cin.getline(sex,20);
        //cin >> id;            

        if(id!=0)
        {
            q = new node;
            q->id = id;
            strcpy(q->name,name);
            strcpy(q->sex,sex);

            q->next = NULL;

            p->next = q;
            p=p->next;
        }

        else   //退出输入
        {
            flag = false;
        }
    }

    
    
    return h;
}

void Print(pnode h)
{
    pnode q= h->next;
    if(q==NULL)
    {
        cout << "链表为空！" << endl;
        return;
    }

    cout << "打印链表：" << endl;
    int i=0;
    while(q!=NULL)
    {
        cout <<  "节点"<<i++ << "\t"<< "学号："<< q->id << "姓名："<<  q->name <<"性别："<< q->sex << endl;
        q=q->next;
    }

}

int Length(pnode h)
{
    pnode p=h->next;
    int n = 0;
    while(p!=NULL)
    {
        n++;
        p = p->next;
    }
    return n;
}

void Delete(pnode h,int num)
{
    pnode p1 = h->next;
    pnode p2;
    if(p1==NULL)
    {
        cout << "链表为空！无法查找"  << endl;
        return;
    }

    while (p1->id!=num && p1->next != NULL)
    {
        p2= p1;
        p1 = p1->next;
    }

    if(p1->id == num)
    {
        if(p1 == h)     //在h头
        {
            p1 = h;
            h = h->next;
            delete p1;   //释放掉头节点
        }
        else if (p1->next == NULL)
        {
            delete p1;
            p2->next = NULL;
        }
        else
        {
            p2->next = p1->next;
            delete p1;
        }
        cout << "删除节点成功" << endl;
    }
    else
    {
        cout << "没有查找到对应节点，无法删除\n";
    }
}

void Sort(pnode h)
{
    if(h == NULL)
    {
        cout << "链表为空！无需排序" <<endl;
        return;
    }
    pnode p,q;
    p=h->next;
    while(p->next!=NULL)
    {
        q=p->next;
        while(q!=NULL)
        {
            if(q->id < p->id)
            {
                node temp;
                temp.id= p->id;
                strcpy(temp.name , p->name);
                strcpy(temp.sex, p->sex);

                p->id = q->id;
                strcpy(p->name, q->name);
                strcpy(p->sex,q->sex);

                q->id = temp.id;
                strcpy(q->name,temp.name);
                strcpy(q->sex,temp.sex);


            }
            q = q->next;
        }
        p = p->next;
    }
    cout << "排序完成，输出：" << endl;
    Print(h);

    
}

//插入操作，这里插入操作如果是在头节点之前会出现错误，所以要给链表一个头节点来避免错误
//原因：这里函数的形参h是指针的值传递，在退出该函数后，指针的值并没有发生变化，因为传递的只是一份形参。在Insert中的所有操作是对指针的值的拷贝的操作，在函数中改变指针的值（h=s）其实是对h的拷贝的改变，所以函数执行完后，原来实参的值并没有发生改变
//

void Insert(pnode h,int num,char * name,char * sex) 
{
    pnode p1,p2;
    p1 =h->next;
    pnode s = new node;
    s->id = num;
    strcpy(s->name,name);
    strcpy(s->sex ,sex);
    if(h== NULL)
    {
        h = s;
        cout  << "插入成功" << endl;
            Print(h);
        return;
    }

    while (p1->id<s->id && p1->next!=NULL)
    {
        p2 = p1;
        p1 = p1->next;
    }

    if(p1==h->next)
    {
        if(p1->id>s->id)
        {
            h->next = s;
            s->next = p1;            
        }
        else
        {
            p1->next = s;
            s->next = NULL;
        }
        
    }
    else if(p1->next == NULL)
    {
        p1->next = s;
        s->next = NULL;
    }
    else
    {
        p2->next = s;
        s->next = p1;
    }
    Print(h);
    


}